The present invention relates to pumps, and in particular to a rotary pump having a magnetic clutch for coupling an impeller shaft to a motor for driving the shaft.
Industrial spray coating systems, for applying coatings of paint or other material to ware, often use a central supply system for providing the material to a plurality of coating stations. A supply of the material is contained in a tank, and is pumped through supply lines to various stations where coating equipment, such as spray guns, is connected with material in the lines. Where the material is of a type that settles upon standing, such as paint, the system preferably is of a circulating type that maintains the paint in motion. With such systems, paint is pumped from the tank through a line extending past all of the spraying stations, and then returned to the tank. A mixer in the tank agitates the paint, and couplings in the line at the stations allow spray paint equipment to connect to the line.
Conventionally, pumps for such systems are of the motor driven turbine type, consisting of one or more pumping stages. A disadvantage of such prior pumps is that the motor output is mechanically connected to the pump impeller shaft, requiring the shaft to extend through the pump housing in a rotary seal that is prone to leakage and frequent replacement. Also, should the pump become jammed as a consequence of induction of foreign matter, because of the mechanical connection one or both of the motor and pump may be damaged.